A British aid worker who died on Friday in Jenin refugee camp was killed by Israeli gunfire, Israeli public radio has reported.

Iain Cook was shot by accident as he left his caravan with a mobile phone in his hand, according to an initial investigation by the Israel Defence Forces (IDF), the radio says.

A soldier thought it was an attempt to attack

Israel Radio quoting findings of initial investigation

"From the first results of the enquiry, it appears that the shots came from the Israeli side, and that a soldier fired in error at the employee," the investigation has found, Israel Radio said on Saturday.

The development comes after the United Nations expressed serious concerns about the killing and accused Israel of delaying an ambulance trying to reach the man.

UN Secretary General Kofi Annan said on Friday he was "deeply disturbed" by the death of Mr Hook, 53, who was working for the UN agency for Palestinian refugees (UNRWA) at the Jenin refugee camp.

He was involved in a project to rebuild homes which were destroyed during previous Israeli operations.

In a separate incident, Caoimhe Butterly, a young Irish woman active in a Palestinian solidarity group, told Irish radio she had been shot in the foot while trying to protect Palestinian children during the incursion.